Route reliability record
HLN→DEN
Helena to Denver
- Flights
- 783
- Period
- September 2025 to August 2026
- Distance
- 594 mi
- Carriers
- 1
This route earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 783 HLN to DEN flights, with a median arrival 13 minutes early.
Best time to fly HLN to DEN: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 90.1% of the time and Tuesday flights 87.4%, against 84.0% for the route overall.
Set against the rest of the country, this route's record is 7 points better than the US average of 77.3%. That gap is worth roughly 67 fewer late arrivals for every thousand flights.
Key figures
On time
84.0%
Arrivals under 15 minutes late, of 774 completed flights
Avg delay
103 min
Across delayed arrivals only, not all flights
Cancelled
0.38%
National rate is 1.89%
Best carrier
SkyWest
84.0% on time across 783 flights
These figures cover 783 flights between September 2025 and August 2026. The median arrival is 13 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Which airline is most reliable on HLN to DEN
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 783 | 84.0% | 103 min | 0.38% | B+ |
Flight by flight
Flights on HLN to DEN
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against half a point between the best and worst carrier.
- 5am–8am365 flights90.1%
- 8am–11am—
- 11am–2pm—
- 2pm–5pm363 flights79.8%
- 5pm–8pm55 flights70.9%
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.1% of the time, against 70.9% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 365 flights scheduled in it.
Explore
Filter HLN to DEN by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On HLN to DEN, the best departure window is 5am–8am at 90.1% on time and the worst is 5pm–8pm at 70.9%, a wide gap of 19.2 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am90.1%
- 8–11am—
- 11am–2pm—
- 2–5pm79.8%
- 5–8pm70.9%
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 21 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 72.9% on time, 21 points below May, the best at 93.5%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. September was the busiest month here, with 90 flights.
Across the week, Tuesday is the strongest day at 87.4% on time and Saturday the weakest at 79.8%, a spread of 8 points.
Delay causes
Why this route gets delayed
Carrier accounts for 46% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Carrier
- 23%National Airspace System
- 16%Extreme weather
- 15%Late-arriving aircraft
Extreme weather accounts for 16% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.6 times the usual weather exposure. The split is drawn from 12,742 reported delay minutes.
The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,901 of the 13,000 delay minutes reported here.
Cancellations are rare at 0.38%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
7.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last close to two hours, which a normal layover absorbs.
The 594 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 80.9% on time across 783 flights, 3 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
One caution: this is a thin sample. 783 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in DEN after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 783 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 774 completed flights over 12 months sit behind that.
Common questions
HLN to DEN questions
How often is HLN to DEN delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.0% of the 783 flights in this analysis, against 22.7% nationally. Delayed flights are late by close to two hours on average.
How reliable is HLN to DEN compared with the rest of the country?
84.0% of flights arrive on time here against a national 77.3%, a difference of 7 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on HLN to DEN?
The 5am–8am departure window is the strongest at 90.1% on time. The 5pm–8pm window is the weakest at 70.9%, 19 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on HLN to DEN?
June is the weakest month at 72.9% on time, compared with 93.5% in May. Across the year that is 21 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DEN to HLN — the return legseparate record
- Denver International (DEN) delay statistics
- HLN to SLC, a related route95.4%
- PHX to DEN, a related route76.7%
- SLC to DEN, a related route79.0%
- SkyWest Airlines on-time record84.0%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. HLN to DEN and DEN to HLN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed HLN to DEN’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.